1. Field of the Invention
The present invention relates to an image forming apparatus, an image adjusting method, and a program product.
2. Description of the Related Art
Image adjustment including positional deviation correction and density correction is performed by forming a test pattern image with a toner on an intermediate transfer belt and then detecting the image with a sensor in a copying machine or a multi function peripherals (MFP) that is equipped with a plurality of functions such as a copying machine, a facsimile, and a printer in a housing (for example, Japanese Patent No. 4359199).
A normal image print cannot be performed during such image adjustment. Thus, frequent image adjustment causes a problem in that the number of times that a print operation cannot be performed due to image adjustment or, namely, downtimes increases and this decreases the productivity of the apparatus. A method in which a test pattern image is formed at a main-scanning direction edge outside the print region and the test pattern image is detected in parallel with the image print is known as a method for reducing the number of downtimes. This can perform image adjustment while printing an image in real time.
Japanese Laid-open Patent Publication No. 2006-293240 discloses that a configuration configured to switch a mode in which a test pattern image is formed at a main-scanning direction edge at the outer side of a transfer sheet depending on the width of the transfer sheet and a mode in which the interval between the sheets is extended in order to form a test pattern image at the main-scanning direction edge between the sheets, for example, when the test pattern image cannot be formed at the main-scanning direction edge at the outer side of the transfer sheet.
However, there is a problem, even in the configuration described in Japanese Laid-open Patent Publication No. 2006-293240, in that forming a test pattern image with extending the interval between the sheets reduces the throughput. As described above, the apparatuses in the past have a problem in that the throughput is reduced when the transfer sheets have different sizes, for example, because of print jobs for transfer sheets having different sizes while test pattern images are formed at the main-scanning direction edges outside the print regions over a plurality of pages in parallel with the image print.
In light of the foregoing, an objective of the present invention is to provide an image forming apparatus, an image adjusting method, a program and a computer-readable storage medium that are capable of adjusting an image without reducing the throughput.